Alien was released in
1979, and Aliens in 1986. All of the movies in
this series, including Alien 3 (1992) and Alien
Resurrection (1997) were science fiction horror flicks.
The 1979 movie was both a box office and critical
success, actually earning a number of awards. The
1986 movie did even better. All films starred
Sigourney Weaver as Ellen Ripley.

In the 1979 movie, a
spaceship called the Nostromo is on the way back to
earth is asked to investigate a strange signal coming
from a nearby planet and alien ship. While
exploring the ship, they find a chamber full of eggs.
One of the eggs hatches, attacks one of the crew, and
all hell breaks loose from there as the alien hatchling
begins killing off the crew.

Aliens (1986) finds
the only surviving crew member of the Nostromo, Lt.
Ellen Ripley (Weaver), waking up after 57 years of
hypersleep. Ripley is shocked to find out that the
planet from which she had escaped was being teraformed,
and that the crew on the planet could no longer be
reached. The rest of the movie was about Ripley's
return trip to the planet with a group of die hard
Marines, who fight for their lives as the aliens pick
them off one by one.